Generally, angles of a headrest of a sofa can be adjusted to improve comfort. One of the achievement manners is to set an adjuster having a pivotal joint in the sofa. The current adjuster mainly includes two types, one of which is a hinge to merely adjust the angle of the headrest, another of which is a linkage mechanism with hinges to fine adjust the height of the headrest during the angle adjusting, so as to prevent wrinkles or extensions generated on the sofa surface.
During actual using, user may respectively adjust the height or the angle of the headrest, for example, only adjusts the height rather than the angle, but the current adjuster cannot meet such a demand.
Thus it's necessary to provide an adjusting device for respectively adjusting the angle and the height of the headrest.